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Finding the Fourth Proportional to 787.78, 1,086.72 and 456.13

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Solution

The fourth proportional to 787.78, 1,086.72 and 456.13 is: 629.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.78 : 1,086.72 = 456.13 : x
  2. Step 2: Convert to fraction form
    787.78/1,086.72 = 456.13/x
  3. Step 3: Cross multiply
    787.78x = 1,086.72 × 456.13
  4. Step 4: Simplify right side
    787.78x = 495,685.24
  5. Step 5: Solve for x
    x = 495,685.24/787.78
  6. Step 6: Final answer
    x = 629.22

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.